Brian Wilson #38 of the San Francisco Giants sits in the dugout during their game against the Arizona Diamondbacks at AT&T Park on September 4, 2011 in San Francisco, California.

Photo: Ezra Shaw, Getty Images

Brian Wilson #38 of the San Francisco Giants sits in the dugout...

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San Francisco Giants relief pitcher Brian Wilson waves to the fans after warming up for their game with the Pittsburgh Pirates Friday, April 13, 2012, in San Francisco Calif.

Photo: Lance Iversen, The Chronicle

San Francisco Giants relief pitcher Brian Wilson waves to the fans...

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FILE - In this July 10, 2011, file photo, San Francisco Giants pitcher Brian Wilson adjusts his neck during the ninth inning of a baseball game against the New York Mets in San Francisco. Wilson is likely headed for surgery on his right elbow after an MRI showed structural damage and an issue with the ligament, and his season could be in jeopardy. Manager Bruce Bochy and athletic trainer Dave Groeschner say the club will seek at least one other opinion and probably two, including from the renowned orthopedist Dr. James Andrews, who performs Tommy John elbow-reconstruction surgeries. (AP Photo/Ben Margot, File)

Photo: Ben Margot, Associated Press

FILE - In this July 10, 2011, file photo, San Francisco Giants...

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Brian Wilson #38 of the San Francisco Giants pitches in relief against the Colorado Rockies at Coors Field on April 11, 2012 in Denver, Colorado. The Rockies defeated the Giants 17-8.

DENVER, CO - APRIL 12: Brian Wilson #38 of the San Francisco Giants shakes hands with third base coach Tim Flannery of the San Francisco Giants after defeating the Colorado Rockies 4-2 at Coors Field on April 12, 2012 in Denver, Colorado. (Photo by Justin Edmonds/Getty Images)

Photo: Justin Edmonds, Getty Images

DENVER, CO - APRIL 12: Brian Wilson #38 of the San Francisco Giants...

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DENVER, CO - APRIL 12: Relief pitcher Brian Wilson #38 of the San Francisco Giants works the ninth inning against the Colorado Rockies at Coors Field on April 12, 2012 in Denver, Colorado. The Giants defeated the Rockies 4-2. (Photo by Justin Edmonds/Getty Images)

Moving on will be easier if the Giants get starts from Barry Zito such as the one he delivered Saturday: The lefty went seven innings and allowed three runs, two earned.

Zito knows how important Wilson is.

"He's a huge impact player," Zito said. "He can change the whole dynamic of a team, both on the field and off the field. It's a huge blow."

Wilson might see Dr. James Andrews, who examined him in August. The man known for his nasty slider and distinctive beard went on the disabled list soon thereafter and made only two more appearances in 2011.

The Giants insisted during the offseason that there wasn't any structural damage to his elbow. For someone who underwent Tommy John surgery when he was at LSU, Saturday's news had to hit Wilson hard.

"Spring training went well with the rehab," Bochy said. "We checked off every box with him, back-to-back days. It looked like he was all set to go, and then this happened."

Wilson declined to speak with reporters Saturday. Through a Giants spokesman, Wilson said he will talk Sunday.

He made his 2012 debut in the Giants' 17-8 loss at Colorado on Wednesday. He picked up the save - even though he allowed a run on three hits and a walk - in their 4-2 win Thursday.

During Thursday's ninth inning, Wilson appeared hurt, and Bochy and head trainer Dave Groeschner visited the mound. Wilson finished the game, though he apparently was hiding his pain.

"Just talking to him today," Groeschner said, "he definitely felt something the other day. He didn't tell us that the other day."

You can make the case Wilson was as important as any member of the Giants in their World Series-winning season of 2010. He tied Rod Beck's franchise record with 48 saves and had a 1.81 ERA. In 11 2/3 postseason innings, Wilson went 1-0 with six saves and did not allow an earned run.

He wasn't quite as dominant last season, but still went 6-4 with a 3.11 ERA and 36 saves. When Wilson went on the disabled list in mid-August, Bochy employed a closer-by-committee approach. Santiago Casilla went 6-for-6 in save opportunities in that stretch.

For the short term, anyway, Bochy said he'll use his bullpen in a similar fashion. Casilla entered a 3-3 game in the eighth Saturday night and recorded five outs. Javier Lopez struck out the only batter he faced to pick up the win.